1. Technical Field
Various embodiments relate to a semiconductor apparatus, and more particularly, to a semiconductor apparatus for controlling a back bias.
2. Related Art
A semiconductor apparatus typically includes circuits designed using MOS (metal oxide semiconductor) transistors. An MOS transistor may be turned on when a voltage that is relatively higher than a threshold voltage is received at the gate and a current path is formed between the drain and the source. A back bias may be applied to the bulk of the MOS transistor to control the threshold voltage. The back bias may prevent data from being lost in an unnecessary PN junction, and may prevent a latch-up phenomenon of the transistor from occurring.
FIG. 1 is a circuit diagram representation of an example of a typical semiconductor circuit, an inverter 10. The inverter 10 may include a P channel MOS transistor (a PMOS transistor) 11 and an N channel MOS transistor (an NMOS transistor) 12. The inverter 10 may generate an output signal OUT when one of the two transistors is turned on based on the level of an input signal IN. In general, during the operation of the inverter 10, a power supply voltage VDD may be applied to the bulk of the PMOS transistor 11 as a back bias and a ground voltage VSS may be applied to the bulk of the NMOS transistor 12 as a back bias. It is desirable that, when there is no input signal IN supplied to the inverter 10, the PMOS transistor 11 and the NMOS transistor 12 turn off and current consumption ceases. However, there is typically leakage current due to the characteristics of the transistors.